Electrical floor boxes are typically installed in a floor to house electrical components and provide a connection to electrical, communication and other wiring routed under and through the floor of a building structure. Such floor boxes generally must be mounted substantially flush with the upper surface of the floor. Various buildings have floors of different types, materials and thickness. For example, electrical floor boxes may be installed in a concrete floor, such as in an exhibition center, arena or office building, or in a joisted or raised floor, such as in a house. Some construction sites may utilize both concrete and raised floors. Each type of floor presents different requirements for positioning and mounting a floor box with respect to the floor. Currently, when floor boxes are installed, electricians must bring to the construction site multiple types of brackets, shims and mounting devices so as to be prepared to install floor boxes in either type of floor. If the electrician has the wrong equipment for installation of the box, the electrician may need to leave the construction site to obtain the proper installation devices, thereby resulting in added time for completion of a job.
Concrete floors are commonly constructed in a couple of manners. For example, a concrete floor can simply be poured onto a leveled dirt surface, such as for the ground level. Alternatively, the floor may be constructed by pouring concrete in steel forms, such as for upper levels of a building structure. Cable plenums for wiring the structure are typically pre-located on the leveled dirt or within the steel form structure, and are located under the floor once the concrete is poured. In order to connect to source power and signal cables running through such cable plenums, the plenums must be accessed by a hole formed through the concrete and the steel. Forming such a hole in an existing concrete floor for installing a floor box can be expensive, dirty, and disruptive to other uses of the area surrounding the intended in-floor box location. Thus, electrical floor boxes customarily are installed, prior to pouring the concrete floor, into pre-designated or pre-framed clearance holes where the boxes rest directly on the leveled dirt surface or within the steel form structure. Depending on floor thickness, different box wall heights may be required to bring an upper edge of the in-floor box level with the desired floor level. Additionally, with concrete floors, it is critical to ensure that the floor box is level before the concrete is poured so that the upper surface of the floor box is flush with upper surface of the concrete floor.
Electrical floor boxes also can be used in floor structures built with raised floor designs, such as board-on-joist floor designs. Board-on-joist floors can include traditional wood flooring as well as laminate, linoleum, carpeting, or other flooring material supported on a joisted sub-floor. In a board-on-joist floor design, cable plenums are located between the joists. A cable plenum under a board-on-joist floor can be accessed relatively quickly and without significant cost or disruption of the surrounding area. However, actually installing a floor box into an existing board-on-joist floor can be challenging. In particular, firmly fastening the box to the floor can be difficult because many flooring materials do not accept or retain conventional fasteners, or may interfere with penetration of fasteners into the sub-floor or joists. In particular, stone or ceramic tiles and some types of wood-finish resin laminates can frustrate most desirable methods of fastening a floor box in the floor. Ceramics are particularly frustrating because incautious fastening efforts can destroy the tile flooring. Fastening the floor box to the floor structure is further made more difficult by a desire to minimize secondary cuts or holes drilled in the flooring material, since each additional cut or hole further weakens and detracts from the appearance of the flooring material.
In view of the foregoing, there is a need for an effective and inexpensive device for locating an electrical floor box at an appropriate height above a steel form for concrete floors. Also, there is a need for an effective and inexpensive device for firmly attaching a floor box to a raised floor. Ideally, a single device capable of addressing both needs, especially a device that can be removably attached to the floor box and adjusted into desired position and orientation once attached, is desirable. Accordingly, it is a general object of the present invention to provide an electrical floor box assembly that overcomes the problems and drawbacks associated with installation of a floor box in a concrete floor structure as well as a raised floor structure.